Electrical inductive apparatus having means to prevent contamination



Sept. 6, 1966 coss -r 3,271,714

-ELECTHICAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATIONFiled Jan. 15, 1965 5 Sheets-Sheet l PRIOR ART WITNESSES INVENTOR mRaleigh J Cossourt I AT ORNEY Sept. 6, 1966 R. J. COSSAART 3,271,714

ELECTRICAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATION 5Sheets-Sheet 2 Filed Jan. 15, 1965 Sept. 6, 1966 R. J. COSSAART3,271,714

ELECTRICAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATION 5Sheets-Sheet 3 Filed Jan. 15, 1965 United States Patent 3,271,714ELECTRHCAL INDUCTIVE APPARATUS HAVING MEANS TO PREVENT CONTAMINATIONRaleigh J. Cossaart, Muncie, Ind., assignor to Westinghouse ElectricCorporation, Pittsburgh, Pa, a corporation of Pennsylvania Filed .lan.15, 1965, Ser, No. 425,725 4 Claims. (Cl. 33690) This invention relatesin general to electrical inductive apparatus, such as transformers, andmore particularly to an enclosure for electrical inductive apparatus.

The demand for transformers with higher voltage and higher kva. ratingshas created shipping problems for the manufacturers, as higher voltageand kva. ratings mean a corresponding increase in the physical size ofthe transformer. Bridge, tunnel, and other obstacles on the shippingroutes dictate the maximum physical size of any one component of thetransformer. At first, the problem was solved by merely removing thetransformer bushings, and install-ing them at the point of use. Thisnecessitated opening the transformer enclosure or tank for only theshort period of time required to install the bushings through openingsin the tank wall or top, and contamination of the transformer insulationand liquid dielectric was not a serious problem. As the physical size ofthe transformers continued to increase, however, removing the bushingsdid not solve the problem. It became necessary to take advantage of thefact that the enclosure or tank was considerably higher than theenclosed core-coil assembly, by sectionalizing the enclosure. Insectionalizing the transformer enclosure, a first or lower section ofthe transformer enclosure is constructed which is only high enough toclear the enclosed core-coil assembly, and a shipping cover provided toenclose the unit for shipping. A second or upper section of thetransformer is constructed to complete the enclosure to the desiredheight. At the point of use, the shipping cover is removed, and thelower and upper sections are assembled. The electrical bushings may thenbe mounted and electrically connected. While this procedure solved theimmediate shipping problem, it produced other equally serious problems.The removal of the shipping cover exposes the transformer core and coilassembly and its liquid dielectric to the atmosphere for a much longertime than when it was merely necessary to insert electrical bushings,resulting in the possibility of weakening the coil insulation and theinsulating value of the cooling dielectric through the addition ofmoisture or water vapor into the enclosure, as well as other foreignmaterial which may have a deleterious effect on the useful operatinglife of the unit.

Accordingly, it is an object of this invention to provide a new andimproved enclosure for electrical inductive apparatus.

A further object of the invention is to provide a new and improvedsectionalized enclosure for electrical transformers.

Another object of the invention is to provide a new and improvedenclosure for electrical transformers that allows the transformers to beshipped sectionalized and reassembled at the point of use, exposing theelectrical coils and liquid dielectric to the atmosphere forsubstantially the same period of time as an unsectionalized transformer.

Briefly, the present invention accomplishes the above cited objects byproviding a sectionalized tank or enclosure in which the shipping coveris a permanent portion of the enclosure. The shipping cover containscovered openings for the electrical bushings, tap changer shafts, andthe like. In the field, the top section is installed in position overthe shipping cover, before the covered openings on the shipping coverare removed. Thus, the trans former coils and liquid dielectric areexposed to the atmosphere for only the short period of time required toinsert the electrical bushings, the same as for an unsectionalizedtransformer.

Further objects and advantages of the invention will become apparent asthe following description proceeds and features of novelty whichcharacterize the invention will be pointed out in particularity in theclaims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to theaccompanying drawings, in which:

FIGURE 1 is a perspective view, partially cut away, illustrating atypical prior art sectionalized transformer arrangement;

FIG. 2 is a perspective view illustrating one section of a transformerenclosure constructed according to the teachings of this invention;

FIG. 3 is a perspective view, illustrating another section of atransformer enclosure constructed according to the teachings of thisinvention; and

FIG. 4 is a perspective view, partially cut away, of an assembledsectionalized transformer enclosure constructed according to theteachings of this invention.

Referring now to the drawings, and FIGURE 1 in particular, there isillustrated a perspective view, partially cut away, of a prior artsectionalized transformer 10. Transformer 10 includes high and lowvoltage windings 12, disposed in inductive relation with a magnetic core14. The windings 12 and magnetic core 14 are disposed within a metallictank or enclosure 22, which is constructed in two compartments orsections, a lower section 24, and an upper section 26. High voltagebushing members 16, 18 and 20 are mounted on suitable bushing mountingmeans through openings in the upper section 26 of enclosure 22, and eachhave an internal conductive rod 17, 19 and 21, respectively, connectedto electrical windings 12. Low voltage bushing memlbers, tap changers,indicating instruments, and heat exchangers, are not illustrated forpurposes of simplicity.

It will be noted that considerable space is provided between the top ofthe electrical windings 12 and the top portion 27 of upper enclosuresection 26. This space is necessary for providing electrical clearances,allowing expansion of the liquid dielectric, and the mounting of tapchangers, and the like. In sectionalizing electrical transformers toreduce their overall height for shipping purposes, the transformerenclosure 22 is divided into lower and upper sections, 24 and 26,respectively, with the lower sections 24- being of suflicient height toenclose the core 14 and electrical windings 12. A shipping cover (notshown) is provided over the lower section 24, and the lower section 24,upper section 26, electrical bushings 16, 18 and 20, and otheraccessories, are all separately shipped to the point of use for fieldassembly. The field assembly includes removal of the shipping cover fromthe lower enclosure section 24, and placement of the upper enclosuresection 26 on the lower enclosure section 24. The upper and lowerenclosure sections, 26 and 24, include mating flanged portions 32 and34, respectively, and a plurality of bolts 36 are inserted throughmating openings in the flanged portions 32 and 34 and engaged bysuitable nuts to firmly secure the upper and lower sections 26 and 24together. A gasket member (not shown) is inserted between the matingflanges 32 and 34 before assembly to insure that the enclosure 22 willbe fluid tight.

The removal of the shipping cover from the lower enclosure section 24necessarily subjects the windings 12 and liquid dielectric to theatmosphere for a relatively long period of time, resulting in thepossibility of contaminating the liquid dielectric with moisture andforeign bodies, and weakening the coil insulation. Since moisture andforeign material may seriously impair the operating -13 life of highvoltage transformers, it would be desirable to reduce the amount of timethe windings 12 and liquid dielectric are subjected to the atmosphere toan absolute minimum.

This invention allows transformers to be sectionalized for shipment, andyet allows the lower enclosure section 24 to be open to the atmosphereduring field reassembly for only a very short period of time, a periodwhich is substantially the same as for unsectionalized transformers.

FIGS. 2 and 3 are perspective views of a transformer enclosure,illustrating lower and upper metallic enclosure sections, 40 and 42,respectively, constructed according to the teachings of this invention.Instead of constructing the lower section 40 with a temporary shippingtop, a top 44 is permanently secured to the lower section 40, bywelding, or other suitable means. Top 44 contains a plurality ofcoverable openings, such as openings for receiving high voltage bushingassemblies, sealed by covers 46, 48 and 50, openings for receiving lowvoltage bushing assemblies sealed by covers 52, 54 and 56, an openingfor allowing cooling dielectric to enter the upper enclosure section 42,sealed by cover 58, and other sealed openings (not shown) for tapchanger shafts, indicating instruments, and the like. The top or cover44 may extend beyond the sides of lower enclosure 40 for a predetermineddistance to form a flanged portion 60. Flanged portion 60 has aplurality of openings 62 disposed therein for receiving suitablefastening means, such as bolts.

Top 44 may be constructed of metal, such as steel, or it may be formedof a suitable electrical insulating material. If the latter, the flangedportion 60 may be part of the lower section 40. v

The upper section 42 includes a flanged Portion 64, which has aplurality of openings 66 disposed therein for receiving fastening means,and a plurality of additional openings, such as openings 68, 70 and 72having means, such as bushing bosses 69, 71 and 73, for receiving highvoltage bushing assemblies, openings 74, 76 and 78 having means, such asbushing bosses 75, 77 and 79 for receiving low voltage bushings, and asuitable access opening sealed by cover 80. Thus, lower section 40 andupper section 42 are shipped to the point of use for field assembly, asshown in FIGS. 2 and 3.

' FIG. 4 is a perspective view illustrating the lower and upperenclosure sections 40 and 42 of FIGS. 2 and 3, assembled and ready forthe mounting of the electrical bushing members. More specifically, theupper section 42 has its open bottom portion disposed over the lowersection 40, with the openings 62 and 66 in the flanged portions 60 and64, respectively, being aligned. Suitable fastening means, such as bolts82 are inserted into the aligned openings 62 and 66, and secured firmlywith suitable nuts. A gasket member (not shown) is disposed between themating flanged portions 60 and 64 before assembly to insure a fluidtight seal between the upper and lower sections. Once the upper section42 is secured to the lower section 40, the covers 46, 48, 50, 52, 54,56, and 58 may be removed from the top 44, or they may be loosened andall the fastening means removed but one. The covers may be rotated aboutthe remaining single fastening means, such as bolt 90, to a positionwhich allows complete access to the opening, and then tightened tosecure the cover in its new position. The covers are thus readilyavailable in the event the transformer has to be moved again. Thus, theassembly of the upper and lower sections 42 and 40, and associatedcomponents may be accomplished without opening the lower section 40 tothe atmosphere. It is only when the bushings are ready for mounting thatthe lower section 40 need be opened, and then only small openings aremade, just as though the transformer were of the non-sectionalized type.When the upper and lower sections 42 and 40 are assembled, openings 46,48 and 50 are aligned with openings 68, 70 and 72, respectively, andopenings 52, 54 and 56 are aligned with openings 74, 76 and 78respectively. The bushing members, such as bushing member 81, are

then mounted on the bushing mounting means, with the lower portion ofthe bushing extending into the lower compartment through theappropriately aligned opening. After the bushing members are mounted,opening 100 may be used to make electrical connections, and opening 100is left in its open position to allow liquid dielectric to freely passfrom the lower section 40 to the upper section 42.

Thus, there has been disclosed a new and improved tank or enclosure forelectrical transformers, which possesses the advantages of sectionalizedtransformers in allowing the transformer to be shipped in sections, andalso the advantages of non-sectionalized transformers, as the enclosedwindings and liquid dielectric are opened to the atmosphere only for thelength of time necessary to install the bushing members.

Since numerous changes may be made in the above described apparatus anddifferent embodiments of the invention may be made without departingfrom the spirit thereof, it is intended that all matter contained in theforegoing description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. Electrical inductive apparatus comprising electrical windings,

a magnetic core,

said electrical windings being disposed in inductive relation with saidmagnetic core,

a first enclosure section having a top portion which has a plurality ofcoverable openings therein,

said electrical windings and magnetic core being disposed in said firstenclosure section, a second enclosure section having a top portion andsidewall portions which define a bottom opening,

said second enclosure section being re'mcvably secured to said firstenclosure section, with the bottom opening in said second enclosuresection being disposed over the top portion of said first enclosure, thetop portion of said second enclosure section having a plurality ofopenings therein,

a plurality of electrical bushing members,

said plurality of electrical bushing members being disposed in theopenings in the top portion of said sec ond enclosure section,

means securing said electrical bushing members to the top portion ofsaid second enclosure section,

and means electrically connecting said bushing members with saidelectrical windings through certain of the openings in the top portionof said first enclosure section.

2. The electrical inductive apparatus of claim 1 wherein the top portionof the first enclosure section is formed of an electrical insulatingmaterial.

3. The electrical inductive apparatus of claim 1 including liquiddielectric means disposed in said first enclosure section to apredetermined level, the openings in the top portion of said firstenclosure section allowing unrestricted expansion of said liquiddielectric means into said second enclosure section.

4. The electrical inductive apparatus of claim .1 wherein certain ofsaid bushing members extend through openings in the top portion of saidfirst enclosure section.

References Cited by the Examiner UNITED STATES PATENTS 1,508,201 9/1924Treanor 220-85 1,524,762 2/1925 Treanor 22085 1,620,411 3/ 1927 Temple22085 1,872,308 8/ 1932 Llewellyn 22085 LEW-IS H. 'MYERS, PrimaryExaminer.

JOHN F. BURNS, ROBERT K. SCHAEFER,

Examiners. D. I. BADER, Assistant Examiner.

1. ELECTRICAL INDUCTIVE APPARATUS COMPRISING ELECTRICAL WINDINGS A MAGNETIC CORE, SAID ELECTRICAL WINDINGS BEING DISPOSED IN INDUCTIVE RELATION WITH SAID MAGNETIC CORE, A FIRST ENCLOSURE SECTION HAVING A TOP PORTION WHICH HAS A PLURALITY OF COVERABLE OPENINGS THEREIN, SAID ELECTRICAL WINDINGS AND MAGNETIC CORE BEING DISPOSED IN SAID FIRST ENCLOSURE SECTION, A SECOND ENCLOSURE SECTION BEING REMOVABLY SECURED SIDEWALL PORTIONS WHICH DEFINE A BOTTOM OPENING, SAID SECOND ENCLOSURE SECTION BEING REMOVABLY SECURED TO SAID FIRST ENCLOSURE SECTION, WITH THE BOTTOM OPENING IN SAID SECOND ENCLOSURE SECTION BEING DISPOSED OVER THE TOP PORTION OF SAID FIRST ENCLOSURE, THE TOP PORTION OF SAID SECOND ENCLOSURE SECTION HAVING A PLURALITY OF OPENINGS THEREIN, A PLURALITY OF ELECTRICAL BUSHING MEMBERS, SAID PLURALITY OF ELECTRICAL BUSHING MEMBERS BEING DISPOSED IN THE OPENINGS IN THE TOP PORTION OF SAID SECONE ENCLOSURE SECTION, MEANS SECURING SAID ELECTRICAL BUSHING MEMBERS TO THE TOP PORTION OF SAID SECOND ENCLOSURE SECTION, AND MEANS ELECTRICALLY CONNECTING SAID BUSHING MEMBERS WITH SAID ELECTRICAL WINDINGS THROUGH CERTAIN OF THE OPENINGS IN THE TOP PORTION OF SAID FIRST ENCLOSURE SECTION. 